1. The frontal sinus
Surgical approach of the frontal sinus
Anatomical variation of the frontonasal recess may play an important role of the frontal
sinusitis. Agger nasi cells contribute to nasofrontal recess obstruction & chronic frontal
sinusitis. Sagital CT scan shows agger nasi cells encroach on the nasofrontal recess.
Frontal sinus trephination & frontal sinus endoscopy
Frontal sinus trephination is indicated for acute purulent frontal sinusitis. Frontal sinus
endoscopy is a modification of the trephination using endoscope for inspection &
interventions.
Recently external frontal sinus puncture in combination with irrigation has been used to
ease the location of the frontal sinus during endonasal frontal sinus operation.
Operative principles A 1 cm incision is made just above the medial end of the eyebrow &
with a .5cm drill hole the anterior wall of the frontal sinus is opened. Under endoscopic
control, irrigation& inspection of the frontal sinus is possible.
External frontoethmoidectomy
External frontoethmoidectomy starts with a slight curved medial & concave incision towards
the medial canthus of the eye straight down to the bone. The incision divides the distance
between the nasal dorsum& the medial canthus in the middle.The frontal sinus is reached
by mostly osteoclastic resection of the lacrimal bone , part of the frontal process of the
maxilla& the frontal sinus floor. Almost 2/3 rd of the bone margin of the frontal sinus
drainage is resected & replaced by a soft tissue scar. This is associated with a very high risk
of contracture & resultant mucocoele >mucopyocoele. Another problem is ocular
movement disturbance with double vision.
Endonasal surgery of the frontal sinus: The FULDA concept
For type I-III frontal sinus drainage, general anaesthesia is required. Surgery on the frontal
recess is usually preceded at least by an anterior ethmoidectomy.
It is important to remove agger nasi cells & to visualize the attachment of the middle
turbinate medially& lamina papyracea laterally. The anterior skull base with the anterior
ethmoidal artery superiorly.

2. Type I: simple drainage
Simple drainage is established by ethmoidectomy including cells septa in the region of the
frontal recess. The inferior part of the infundibulum & its mucosa is not touched. This
approach is indicated in minor pathology in the frontal sinus.
Type II: Extended drainage
Extended drainage is achieved by resecting the floor of the frontal sinus between the lamina
papyracea & the middle turbinate (type IIa) or the nasal septum (type IIb) anterior to the
ventral margin of the olfactory fossa.
Type III: Endonasal median drainage
The extended IIb opening is enlarged by resecting portions of the superior nasal septum in
the area of the frontal sinus floor. The diameter of the opening should be about 1.5cm. This
is followed by resection of the frontal sinus septum or septa if more than one. Starting on
one side of the patient , the midline is crossed until the contralateral lamina papyracea is
reached (so called frontal T).
Conclusion
Different type of endonasal frontal sinus drainage operation, leaving the bony borders of the outlet
intact & preserving the mucosa as much as possible offer better results than classical external
approach. If endonasal frontal sinus surgery is not expected to be satisfying or endonasal revision
surgery is not successful, the osteoplastic frontal sinus operation via a coronal approach, without
shaving the hair, is the ultimate & more than90% of cases a definite solution. In case of chronic
inflammatory disease, obliteration of the frontal sinus is frequently necessary where as removal of
benign tumours with preservation of of frontal sinus mucosa is not necessary.
Osteoma
Osteoma is a benign tumours often originating in the paranasal sinuses. The frontal sinus is the most
frequent location , followed by the ethmoid, maxillary sinus & sphenoid sinus respectively.
Age of presentation is most commonly the second to fifth decade, with a male :Female ratio 3:1.
Paranasal sinus osteomas are most frequently discovered incidentally on radiographs. Differential
diagnosis of paranasal sinus osteomas include fibrous dysplasia or ossifying fibromas. These lesions
may have a similar radiological appearance, but their borders are usually less well defined than
those of osteomas.

3. Specific surgical technique
1) Endonasal procedure:a) The tumour not exending more laterally than a vertical plane
through the lamina propria may be operated on through the endonasal procedure.
b)Osteomas whose point of origin or fixation is in the lower third of the posterior wall of the
frontal sinus are often an indication for endonasal procedure.c) Intracranial extension is not
a contraindication to the endonasal procedure.
2) Osteoplastic flap procedure: via a coronal incision allows for complete tumour resection
with the best aesthetic result. The hair is not shaved to avoid any surgical stigma for the
patient. Mucosa preserve as much as possible.
Fibrous dysplasia
Fibrous dysplasia is a tumour-like lesion of the bone. It is self-limiting, is not encapsulated &
is characterized by replacement of normal bone with cellular fibrous connective tissue
which contains irregular trabecules of immature, nonlamellar, metaplastic bone.
The disease may develop at early age, progress actively during childhood& stabilize in
adulthood. The monostotic form is found more often in female than in male. The disease is
much more common in white population than black.
Clinically three types of fibrous dysplasia are differentiated.
1) Monototic;
2) Polyostotic;
3) McCune-Albright syndrome, which presents as a combination of polyostotic fibrous
dysplasia, skin pigmentation & endocrine dysfunction.
One –third of cases are located in the maxilla or mandible. Sometimes the frontal or
sphenoid sinus is obliterated by the disease.
Deformity & compression of functionally important structures create the main
symptomatology. Optic nerve compression may occur if frontal , ethmoid, sphenoid sinus
are involved.
The monostotic type does not usually progress after puberty.
Ossifying fibroma is the most difficult to distinguish from fibrous dysplasia. It is better
demarcated expansile lesion with smooth margin & tends to be more aggressively
encroaching on the nasal fossae,orbits& paranasal sinuses.
Specific surgical technique; surgery target complete removal of the space-occupying lesion.
Complete resection means a minimal chance of recurrence.

4. Inverted papilloma
Inverted papilloma is a benign , epithelial neoplasm originating from the schneiderian membrane of
the nose & paranasal sinuses. It usually arises from lateral nasal wall, in the middle meatus, often
extending to the ethmoid & maxillary sinuses.
In advance cases, extension into all of the ipsilateral paranasal sinuses mat occur where as
intracranial growth & dura penetration are rare.
Histologically , the inverted papilloma is a tumour in which there is inversion of the neoplastic
epithelium into the underlying stroma rather than proliferation outwards.
Pathogenesis of the lesion still remain unclear, although allergy, chronic sinusitis & viral infection
have been suggested as possible cause.
Inverted papilloma has been reported to arise in all age group.
The most common presenting symptom is unilateral nasal obstruction, often combined with
rhinorrhoea& epistaxis.
Appropriate imaging combing CT & MRI is utmost important in any unilateral space occupying lesion.
MRI is the first imaging modality to perform in the follow up after removal of the tumour.
Inverted papilloma has been associated with high rate of recurrence between 0 to 78%, malignant
transformation, residual disease & tendency towards mulitcentricity. Recurrence actually represents
residual disease inmost cases. So basic problem facing the clinician is to determine adequate
treatment
Midfacial degloving/ the subcranial approach is the appropriate.
Lateral rhinotomy & endonasal approach have been grown importance since the early 1990s.